Suture anchors are commonly employed in situations where soft tissue (muscle, tendons or ligaments) becomes detached from bone and must be reattached or secured to bone. The anchor is generally inserted into a preformed hole in the bone, and one or more sutures or similar filamentary material extends from the anchor and is attached to the soft tissue to be secured to the bone. The anchor may be advanced into the bone by rotating the anchor or tapping the anchor into the bone. Knotless suture anchors have been developed for use in arthroscopic surgery. Insertion guides in the general form of elongated tubes having a pointed distal end have also been developed to assist in locating the preformed hole into which the anchor is inserted.
Currently available suture anchors, however, have limitations in their ability to provide sufficient tensioning of the soft tissue while deploying the anchor into the bone, particularly when used in arthroscopic surgery. Additionally, these anchors do not permit easy readjustment or re-tensioning once the anchor has been advanced into the bone. In current designs, the suture or sutures move in conjunction with the anchor as the anchor is advanced into the bone reducing the amount of control over the tensioning of the soft tissue. Similarly, in most current designs, sutures extend throughout the length of the anchor requiring removal of the entire anchor from the bone to readjust the tension and often precluding the use of guides to help locate the preformed hole.